A strong cup of coffee can be a perfect start to a dreary morning, but that cup of Joe could be raising your blood pressure notably. The rise in blood pressure is a result of caffeine in the coffee. Depending on your health situation, it may be important for you to monitor your blood pressure before your brew that next pot.
Temporary Increase
In 2011, the "American Journal of Clinical Nutrition" published an analysis of the existing research on caffeine as it relates to high blood pressure. After averaging the data of the studies together, the researchers behind the analysis found that drinking the caffeine equivalent of 2 or 3 cups of coffee raises both your systolic and diastolic blood pressure, which are the first and second numbers in the reading. The average increase after the caffeine was 8.1 millimeters of mercury, or points, to the systolic number and 5.7 millimeters of mercury to the diastolic number. The raised blood pressure effect wore off within three hours.
Long-Term Effects
Coffee may be able to temporarily increase your blood pressure, but there does not appear to be a sustained high-blood pressure effect from regular consumption of coffee. In the 2011 meta-analysis, researchers from the Autonomous University of Madrid examined long-term studies of coffee consumption, and found that after two weeks subjects had no appreciable difference between their coffee consumption and non-consumption blood pressure readings. It is likely safe to drink coffee on a regular basis unless you have dangerously high blood pressure already, which the American Heart Association defines as a systolic blood pressure over 160 and diastolic reading over 100.
Population Differences
The caffeine in coffee may affect you differently depending upon your gender, age, weight, disease history or presence of chronic conditions. In 2011, researchers from the University of Maryland published extracted data from the Baltimore Longitudinal Study of Aging that concluded that that caffeine has a significant long-term blood pressure effect on older men. The more coffee men consume in general, the more their systolic blood pressure increases with age. The researchers did not observe the same effect for women in the study. Men over the age of 70 or overweight to obese appear to be particularly susceptible.
Safe Consumption
Ensure that you check with your doctor before drinking coffee if you are already have significantly high blood pressure, and limit your caffeine consumption to a moderate amount, which the University of Illinois defines as 300 milligrams daily, or roughly three cups of coffee, if you have normal blood pressure. Consuming more than this amount may have a substantial impact on your blood pressure.
References
- "Psychopharmacology"; A Critical Review of Caffeine Withdrawal: Empirical Validation of Symptoms and Signs, Incidence, Severity, and Associated Features; Laura M. Juliano and Roland R. Griffiths; 2004
- University of Illinois; Caffeine; May 2010
- "American Journal of Clinical Nutrition"; The Effect of Coffee on Blood Pressure and Cardiovascular Disease in Hypertensive Individuals: A Systematic Review and Meta-Analysis; A. E. Mesas, et al.; August 2011
- "American Journal of Hypertension"; Greater Coffee Intake in Men Is Associated with Steeper Age-Related Increases in Blood Pressure; P. P. Giggey; March 2011
- American Heart Association: Understanding Blood Pressure Readings
